Definition of Karyocyte

Karyocyte: Any cell that possesses a nucleus.

A neuron (nerve cell) is a karyocyte; it has a nucleus. A mature erythrocyte (red blood cell) is not a karyocyte; it lacks a nucleus.

The term "karyocyte" is made up of "kary-" from the Greek "karyon" meaning "nut or kernel" + "-cyte" from the Greek "kytos" meaning a "hollow vessel" = a hollow vessel (a cell) containing a nut or kernel (a nucleus).